This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We recently described a new type of surplus protein myopathy in four patients, from four different families, affected by a mild myopathy or asymptomatic elevated serum creatine kinase levels. Toluidine blue-stained semithin sections of muscle specimens revealed inclusions of different size and shape that did not stain by routine histochemical studies. The sarcoplasmic or endoplasmic reticulum calcium 1 (SERCA1) ATPase and/or calsequestrin reactivity of inclusions, by immunohistochemistry, and the SERCA1- and calsequestrin-increased expression, by immunoblot, suggested that inclusions could be constituted by an excess of proteins normally present in the terminal cisternae of sarcoplasmic reticulum. In order to understand the molecular basis of the myopathy, we planned to perform proteomic studies on patients? muscle. Our data based on one control and one patient suggest that several proteins are differently and/or exclusively expressed in patient?s muscle compared to control?s muscle. Therefore, we want to validate these preliminary results performing the MudPIT on the other samples.